The Chinese salamander is a very rare nocturnal salamander that lives in lakes and streams in the mountains of China. This one is believed to be at least 200-years-old. It measures 4 feet 7 inches long and weighs 104 pounds. These animals are becoming increasingly endangered due to habitat loss.

Maybe that's why this giant was found in a cave in Chongqing Municipality in China. He's since been transferred to a research facility. You can really tell how big he is here with a scientist for scale:

The Associated Press reports of this amazing occurrence captured on video in North Dakota by retired engineer, George Loegering. According to the AP, experts say the phenomenon developed from a rare combination of "cold, dense air, and an eddy in the river."